What is a whale fall?

When whales die and sink, their carcasses—known as whale falls—provide a bounty of nutrients for deepwater creatures.

A whale fall community, including bacteria mats, clams in the sediments, crabs, worms, and a variety of other invertebrates. The 35-ton gray whale carcass originally settled on the seafloor at 1,674 meters depth in 1998. This photo was taken six years later.

The ocean's depths are supplied by nutrients falling down from the surface waters. When whales die and sink, the whale carcasses, or whale falls, provide a sudden, concentrated food source and a bonanza for organisms in the deep sea.

Different stages in the decomposition of a whale carcass support a succession of marine biological communities. Scavengers consume the soft tissue in a matter of months. Organic fragments, or detritus, enrich the sediments nearby for over a year.

The whale skeleton can support rich communities for years to decades, both as a hard substrate (or surface) for invertebrate colonization and as a source of sulfides from the decay of organic compounds of whale bones. Microbes live off of the energy released from these chemical reactions and form the basis of ecosystems for as long as the food source lasts.

At deep sea levels this forms a new food web and provides energy to support single- and multi-cell organisms and sponges, thus adding to the ocean's food chain.